Allogenic stem cell transplantation for bone marrow failure syndrome, experience from the Bone Marrow Transplant Unit at the Clínica de Marly.

Trasplante alogénico de progenitores hematopoyéticos para síndromes de falla medular, experiencia de la Unidad de Trasplante de Médula Ósea de la Clínica de Marly.

Background: Allogeneic hematopoietic stem cell transplantation (allo-SCT) is considered as the treatment of choice for newly diagnosed patients with bone marrow failure syndromes (BMFS) younger than 40 years, and for older patients that have failed immunosuppressive therapy. Methods: This is a retrospective study of BMFS pediatric and adult patients receiving allo-SCT at a single institution from Bogota, Colombia. The primary outcome was five-year overall survival (OS), determined by the Kaplan-Meier method. Log-rank test was used to determine the impact of various factors over OS. In-hospital stay, grade II-IV acute graft versus host disease (aGVHD) and secondary graft failure were explored. Results: Between January 1993 and August 2011, 74 transplants were performed in 70 patients. 70 grafts were obtained from HLA identical siblings, 3 from unrelated umbilical cord blood and 1 from a haploidentical sibling, were obtained from HLA identical siblings, 3 from unrelated CBU and 1 from a haploidentical sibling. Conditioning regimens used were: RIC Cy-Flu-ATG (22), Cy-ATG (33) and Cy (12). 4 patients were conditioned with alemtuzumab containing regimens and 3 with other. Before 2004 most patients received Cs and MTX as GVHD prophylaxis, after 2004 Cs and MMF was used in the majority. Two patients died during the progenitors infusion. Engraftment for 68 evaluable patients at first allo-SCT ocurred at an average of 11.5 days, similarly between conditioning regimens. 10 patients (14%) had secondary graft failure of whom five died at a mean of 178 days after the allo-SCT. Five patients remain alive, two are transfusion-dependent and three succeeded a second allo-SCT. aGVHD occurred in 30% of patients of whom 46.7% died due to related complications; aGVHD was more frequent with ATG non-containing regimens. For a median follow-up of 18.4 months (range: 4.3- 45.3) OS was 69.1% and varied according to conditioning combination (p = 0.0008). There was no significant difference for OS related to age (p = 0.67). A greater but not significant OS was observed for allo-SCT performed after than before 2004 (p = 0.38). Conclusions: This experience showed that allo-SCT is a fundamental therapeutic option for patients with BMFS treated with allo-SCT, offering a better OS regardless the age and year of performance, suggesting an advantage for RIC over other conditioning regimens.